A tape printer known in the art includes a printing head which performs printing on a long printing tape (label tape) line by line, a tape feed unit (including a motor and a feed roller) which forwards the label tape for the subsequent line printing, and a tape cutter which cuts the printing tape conveyed thereto (see Japanese Patent No. 3,433,354).
According to this type of tape printer, a cutting resistance produced when the label tape is cut by the tape cutter under suspension of printing draws the printing tape toward the tape cutter (toward the downstream side). In this case, the printing head faces to a portion of the printing tape shifted toward the upstream side from the portion thereof corresponding to the suspension. When printing is restarted for the next line printing in this condition, a linear missing part where no printing (no dots) is formed is produced between the next line and the line printed immediately before the suspension.
For avoiding this problem, a tape printer control method in the related art creates a line based on the printing data associated with the line before the suspension and prints the created line in such a manner as to overlap this line on the line printed before the suspension at the time of restart of printing, so as not to produce a missing line having no printing.
According to this related-art printer control method, however, the missing part only becomes inconspicuous by the overlap between the missing part and the part created based on the printing data immediately before the suspension. In this case, elimination of the missing part is achieved only by unnatural and wasteful printing, which may lead to deterioration of the printing quality.
Basically, the motor does not rotate along with the shift of the printing tape toward the downstream side caused by the cutting resistance, because the tape drawing direction is equivalent to the direction of speed increase of the gear train. However, the feed roller slightly rotates in the normal rotation direction in accordance with the shift of the printing tape by the amount corresponding to play in the reverse rotation direction produced by the backlash of the gear train. When printing is restarted in this condition, the gear train idles by the amount corresponding to play in the normal rotation direction. In this case, an error is produced in the number of revolutions of the feed roller.